The US government filed a motion on Saturday to intervene and seek dismissal of a lawsuit by a civil liberties group against AT&T Inc over a federal program to monitor US communications.
The suit filed in the US District Court of the Northern District of California accuses AT&T of unlawful collaboration with the National Security Agency in its surveillance program to intercept telephone and e-mail communications between the United States and people linked to al Qaeda and affiliated organisations.
The class-action suit was filed by San Francisco-based Electronic Frontier Foundation on behalf of AT&T customers in January - before reports this week that AT&T and two other phone companies were secretly helping the government compile a massive database of phone calls made in the United States.
In its motion seeking intervention, posted on the court's Web site, the government said the interests of the parties in the lawsuit "may well be in the disclosure of state secrets" in their effort to present their claims or defences.
A hearing is scheduled for June 21 before federal Judge Vaughn Walker.